It’s pretty easy to be incompetent about the “echolalia” network of concepts, as the literature and the research are clustered messes. (I blithely wallowed in unexamined ignorance for years.) I’m going to suggest a taxonomy here for the purposes of clarity of discussion, but keep in mind that your understanding might vary from what I describe (given your individual path to this knowledge):
Imitation: Person A enacts a motor plan, and Person B reenacts it (closely).
• A person’s mirror neuron system can bolster this function.
• As a reenactment, this is a response (not an initiation/elicitation).
• Whether or not this reenactment is done on purpose (i.e., as associated with a conscious effort), or is a reflex, is underspecified for imitation.
◦ When imitation is not a reflex, then it is a typical cognitive function of learning (such as in developing signed or spoken language).
◦ When imitation is a reflex, then we look at the likes of echolalia (and similar), as classified below (which in earlier developmental stages are also related to typical learning).
◦ This all gets muddled by the fact that some amount of cognitive processing becomes increasingly automatic, which is kind of like developing one’s reflex reactions (that are not pathological).
1) Echophenomena: This is an imitation of motions specifically as a motor reflex (that is generally treated as pathological).
a) The imitated event is external to the imitator.
b) As a reflex…
• the reenactment is immediate (where the lag between cause and effect is too insignificant to leave room for attribution of conscious involvement with the effect),
• the form of the imitation is not associated with a conception for the imitator (i.e., the reflex circumvents that symbolizing function); and
• each pairing of cause and effect is a unique, new instance of the event (i.e., there is only one reflex reenactment for a given instance of a trigger).
c) There are a few types of echophenomena:
• Echopraxia: motions in general
• Echolalia: spoken motions (i.e., that usually produce sound)
◦ Echopalilalia: one’s own spoken motions
• Echolalioplasia (which is additionally rare): signed motions
• You can look up a few other types.
d) When a trigger is followed by a rapid sequence of identical reenactments (i.e., with no significant time in between them), then that could be either:
• just one instance of a compound reflex (i.e., this single effect is a unified composition of many identical repetitions);
• a cascade where the each of those occurrences is interpreted not just as an effect, but as the cause of the next instance of the reflex in the sequence (as in some unusual kind of echopalilalia),
• an initial echophenomenon instance followed by a series of repetitions (see below), which are not echoes, or
• something else.
2) Repetition: These are recurring instances (of an earlier imitation).
a) The initial imitation (but not this repetition) might have been an echo reflex, or it might not.
b) There is a span of time between the first reenactment and this one (i.e., this repetition).
c) When this reenactment reoccurs, it does so without an external repetition of the original antecedent.
• This new instance of the reenactment cannot be a reflex in any contemporary medical sense (i.e. the notion of a “delayed reflex” is not medically sound); however,
• it might be characterized as having become a “habit,” “routine,” “compulsion,” or similar.
• It might also be called “practice,” of which repetition is such a typical part as to be definitive.
d) Since it is not a reflex, and not immediate, the reenacted form can become associated with conception for the person as time passes.
3) Scripting: This is repetition (that is treated as) displaying a paucity of diversification.
a) This repetition is routinized; that is to say, it occurs often enough that familiar communication partners are prone to identify it as predictable, as follows:
• The form has come to be paired with some sort of conceptual structure for the signer/speaker (i.e., symbolization has occurred). That conceptual structure can often be:
◦ transparent to familiar partners, but
◦ opaque to unfamiliar partners.
• This type of routinized repetition tends to be a deliberate strategy (even when it is a collection of defaults).
◦ While you are new to a language, you will tend to rely on scripts as well (e.g., “Uno mas cerveza, por favor”), and you might also treat the sounds as unsegmented, unresolved chunks (“oonohmasserveysah porfa vore”).
◦ Sometimes it is the partners who entrench the phrase, as in the familiar reminders, “Inside voice,” “Hands to self,” and, “We don’t put crayons in our nose.”
◦ This is considered to be pathological when it does not diversify enough over time. Usually, that measurement of “enough” is determined by a combination of partner patience and (allegedly standardized) assessments; in other words, it’s pretty arbitrary.
• Scripting is not so much a pathological compulsion (akin to a reflex) as it is a healthy automation. It is a necessary step towards fluency.
b) Optional: An external source tends to be credited as the origin of the scripted form. This gets emphasized unduly, and isn’t anywhere near as important a factor as it’s made out to be.
• External sourcing is a normal part of communication. It gets noticed more by the partners of people who script (see below), so it gets treated as if it were a necessary characteristic of scripting.
• The canonical case is when the source is something like movies, TV, or lyrics, but that’s just because so many partners are equally familiar with that material (and because so many people are left to be attended by a TV); in other words, no one notices when we repeat from unfamiliar sources.
• When it comes to scripting, “mean length of utterance” (MLU) has nothing to do with it (and little to do with anything else). Some short forms are unique in source (e.g., “Kachow!”), but the longer a form, the more likely that it will be unique, and more easily identified.
• The repetition might be a personal alteration or other paraphrase of an original source, such as, “No one can catch Micky Crewes!”
When someone exposes themselves repeatedly to the same source (e.g., watching the same movie over and over), their partners are more likely to be able to identify that source (due to their collateral proximity).
All of this leads to an exaggerated estimation of the importance of external sourcing to scripting. It is not definitive. The crucial function is the routinizing.
c) Palilalia is the frequent repetition of one’s own words. How frequent? Well, it occurred often enough to have bothered a member of the dominant communicative paradigm [DCP] so badly that they decided to point fingers at the person who scared them with their differentness; that is to say, sometimes the label gets applied to people who simply use the same phrases over and over (to the point of irritating someone else).
4) Automatizing: This is repetition (that is treated as) displaying a sufficiency of diversification.
a) Variety tends to distinguish automatizing from scripting (according to the standards of those communication partners who represent the DCP in the person’s environment).
b) To cover the following material well, I needed a separate tutorial (which was a distillation of a large body of work by a whole lot of other people). You are free to work your way through it, but for our current purposes I am just going to quote a small part:
• In a process that is similar to repeatedly pouring water down a hillside, cognitive entities (including motor and other routine structures) become more firmly familiar with use. This fundamental cognitive function is known as automatization. At the “individual” end of a continuum (i.e., when an individual person does this), the process is called entrenchment, and at the “community” end it is referred to as conventionality (i.e., when a group of communication partners all get used to the same pattern). Such automatic units are referred to as relatively fixed (i.e., they do not tend to vary), and they are more easily accessed with increasing degrees of automaticity (i.e., you learn to do things without having to put so much thought and other effort into them… but if your mind wanders, then you can end up driving to the wrong place, saying the wrong name, writing the wrong year on a check, and so on). An expression such as, “Turn left right here” is so common that it can be accessed with trivial need for an active process of composition. Such a phrase is likely to be evoked as a conventionalized unit (i.e., without having to be created out of its parts). And while novel expressions are likely to require more cognitive effort than fixed ones, they not only tend to be composed of fixed units, but can both (a) conventionalize rapidly (e.g., “Just do it”), and (b) fall out of favor with equal velocity (e.g., “Reach out and touch someone”).
c) So we all script to some extent, but when the sources are conventional and diverse, the behavior passes unremarked as automatizing.
Finally, the following is treated as not being a type of imitation (even though it absolutely does develop in association with an appeal to imitation):
Novel Expressions: This is treated as a lack of repetition.
a) Seeming to avoid repetition is called “fluency.”
b) For any given utterance, it is difficult to identify the amount of influence that automatic, conventionalized material has on a person’s intent to do something new. A whole lot of conveyed meanings are wholesale repeats, or minor variations, so the vast majority of material that people speak/sign is greatly automated. That tends to be attributed to the skill known as “fluency,” and is not considered to be pathological; in fact, the pathology lies in an inability to rely on that automaticity and conventionalization.
We had to go through all of that just because some people don’t trust me when I simply declare that “delayed echolalia” is quackery. Now I can more easily support that contention, as follows, and then discuss the effect that this rotten foundation has on the products that are built upon it.